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Jafari S, Kolivand S. Performance of Iterative Reconstruction in Image Space Algorithm in Combination with Automatic Tube Current Modulation Compared to Filtered Back Projection in Brain CT Scan. J Biomed Phys Eng 2024; 14:379-388. [PMID: 39175556 PMCID: PMC11336050 DOI: 10.31661/jbpe.v0i0.2404-1741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/22/2024] [Accepted: 04/01/2024] [Indexed: 08/24/2024]
Abstract
Background High-quality images with minimum radiation dose are considered a challenge in Computed Tomography (CT) scans. Objective The current study aimed to assess the efficacy of the Iterative Reconstruction in Image Space (IRIS) algorithm combined with Automatic Tube Current Modulation (ATCM) compared to Filtered Back Projection (FBP) in brain CT scans. Material and Methods In this cross-sectional study, 200 patients underwent to brain CT scan, and images were then reconstructed using both FBP and IRIS. The CT Number (CTN), noise, and Signal-to-Noise Ratio (SNR) were computed for different tissues from CT images. The performance of two algorithms under different exposure conditions was evaluated using a water phantom. Two experienced radiologists assessed the image quality. Volume CT Dose Index (CTDIvol) and Dose Length Product (DLP) were recorded for each scan. Results FBP reconstruction exhibited higher noise and lower SNR compared to IRIS, both with and without ATCM. Noise levels significantly increased for FBP combined with ATCM. Subjective analysis showed higher performance for IRIS without ATCM compared to other approaches. The mean CTDIvol with and without ATCM was 20.04±3.33 and 36.37±4.65 mGy, respectively. In the phantom study, the noise with IRIS remained lower than that with FBP even with a 42% dose reduction. Conclusion IRIS algorithm can preserve the image quality when radiation dose is significantly reduced by ATCM in brain CT scan. Implementation of IRIS combined with ATCM is recommended for brain CT examinations.
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Affiliation(s)
- Salman Jafari
- Department of Radiology Technology, School of Paramedicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Sohrab Kolivand
- Department of Radiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
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Graafen D, Müller L, Halfmann MC, Stoehr F, Foerster F, Düber C, Yang Y, Emrich T, Kloeckner R. Soft Reconstruction Kernels Improve HCC Imaging on a Photon-Counting Detector CT. Acad Radiol 2023; 30 Suppl 1:S143-S154. [PMID: 37095047 DOI: 10.1016/j.acra.2023.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/08/2023] [Accepted: 03/20/2023] [Indexed: 04/26/2023]
Abstract
RATIONALE AND OBJECTIVES Hepatocellular carcinoma (HCC) is the only tumor entity that allows non-invasive diagnosis based on imaging without further histological proof. Therefore, excellent image quality is of utmost importance for HCC diagnosis. Novel photon-counting detector (PCD) CT improves image quality via noise reduction and higher spatial resolution, inherently providing spectral information. The aim of this study was to investigate these improvements for HCC imaging with triple-phase liver PCD-CT in a phantom and patient population study focusing on identification of the optimal reconstruction kernel. MATERIALS AND METHODS Phantom experiments were performed to analyze objective quality characteristics of the regular body and quantitative reconstruction kernels, each with four sharpness levels (36-40-44-48). For 24 patients with viable HCC lesions on PCD-CT, virtual monoenergetic images at 50 keV were reconstructed using these kernels. Quantitative image analysis included contrast-to-noise ratio (CNR) and edge sharpness. Three raters performed qualitative analyses evaluating noise, contrast, lesion conspicuity, and overall image quality. RESULTS In all contrast phases, the CNR was highest using the kernels with a sharpness level of 36 (all p < 0.05), with no significant influence on lesion sharpness. Softer reconstruction kernels were also rated better regarding noise and image quality (all p < 0.05). No significant differences were found in image contrast and lesion conspicuity. Comparing body and quantitative kernels with equal sharpness levels, there was no difference in image quality criteria, neither regarding in vitro nor in vivo analysis. CONCLUSION Soft reconstruction kernels yield the best overall quality for the evaluation of HCC in PCD-CT. As the image quality of quantitative kernels with potential for spectral post-processing is not restricted compared to regular body kernels, they should be preferred.
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Affiliation(s)
- D Graafen
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.).
| | - L Müller
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
| | - M C Halfmann
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.); German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany (M.C.H., T.E.)
| | - F Stoehr
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
| | - F Foerster
- Department of Medicine I, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (F.F.)
| | - C Düber
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
| | - Y Yang
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
| | - T Emrich
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.); German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany (M.C.H., T.E.); Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (T.E.)
| | - R Kloeckner
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
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Graafen D, Stoehr F, Halfmann MC, Emrich T, Foerster F, Yang Y, Düber C, Müller L, Kloeckner R. Quantum iterative reconstruction on a photon-counting detector CT improves the quality of hepatocellular carcinoma imaging. Cancer Imaging 2023; 23:69. [PMID: 37480062 PMCID: PMC10362630 DOI: 10.1186/s40644-023-00592-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 07/08/2023] [Indexed: 07/23/2023] Open
Abstract
BACKGROUND Excellent image quality is crucial for workup of hepatocellular carcinoma (HCC) in patients with liver cirrhosis because a signature tumor signal allows for non-invasive diagnosis without histologic proof. Photon-counting detector computed tomography (PCD-CT) can enhance abdominal image quality, especially in combination with a novel iterative reconstruction algorithm, quantum iterative reconstruction (QIR). The purpose of this study was to analyze the impact of different QIR levels on PCD-CT imaging of HCC in both phantom and patient scans. METHODS Virtual monoenergetic images at 50 keV were reconstructed using filtered back projection and all available QIR levels (QIR 1-4). Objective image quality properties were investigated in phantom experiments. The study also included 44 patients with triple-phase liver PCD-CT scans of viable HCC lesions. Quantitative image analysis involved assessing the noise, contrast, and contrast-to-noise ratio of the lesions. Qualitative image analysis was performed by three raters evaluating noise, artifacts, lesion conspicuity, and overall image quality using a 5-point Likert scale. RESULTS Noise power spectra in the phantom experiments showed increasing noise suppression with higher QIR levels without affecting the modulation transfer function. This pattern was confirmed in the in vivo scans, in which the lowest noise levels were found in QIR-4 reconstructions, with around a 50% reduction in median noise level compared with the filtered back projection images. As contrast does not change with QIR, QIR-4 also yielded the highest contrast-to-noise ratios. With increasing QIR levels, rater scores were significantly better for all qualitative image criteria (all p < .05). CONCLUSIONS Without compromising image sharpness, the best image quality of iodine contrast optimized low-keV virtual monoenergetic images can be achieved using the highest QIR level to suppress noise. Using these settings as standard reconstruction for HCC in PCD-CT imaging might improve diagnostic accuracy and confidence.
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Affiliation(s)
- Dirk Graafen
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
| | - Fabian Stoehr
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Moritz C Halfmann
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany
| | - Tilman Emrich
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Friedrich Foerster
- Department of Medicine I, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Yang Yang
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Christoph Düber
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Lukas Müller
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Roman Kloeckner
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- Present Address: Institute of Interventional Radiology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
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Park MS, Ha HI, Ahn JH, Lee IJ, Lim HK. Reducing contrast-agent volume and radiation dose in CT with 90-kVp tube voltage, high tube current modulation, and advanced iteration algorithm. PLoS One 2023; 18:e0287214. [PMID: 37319309 PMCID: PMC10270572 DOI: 10.1371/journal.pone.0287214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/31/2023] [Indexed: 06/17/2023] Open
Abstract
Increasing utilization of computed tomography (CT) has raised concerns regarding CT radiation dose and technology has been developed to achieve an appropriate balance between image quality, radiation dose, and the amount of contrast material. This study was planned to evaluate the image quality and radiation dose in pancreatic dynamic computed tomography (PDCT) with 90-kVp tube voltage and reduction of the standard amount of contrast agent, compared with 100-kVp PDCT of the research hospital's convention. Total of 51 patients with both CT protocols were included. The average Hounsfield units (HU) values of the abdominal organs and image noise were measured for objective image quality analysis. Two radiologists evaluated five categories of image qualities such as subjective image noise, visibility of small structure, beam hardening or streak artifact, lesion conspicuity and overall diagnostic performance for subjective image quality analysis. The total amount of contrast agent, radiation dose, and image noise decreased in the low-kVp group, by 24.4%, 31.7%, and 20.6%, respectively (p < 0.001). The intraobserver and interobserver agreements were moderate to substantial (k = 0.4-0.8). The contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and figure of merit of the almost organs except psoas muscle in the low-kVp group were significantly higher (p < 0.001). Except for lesion conspicuity, both reviewers judged that subjective image quality of the 90-kVp group was better (p < 0.001). With 90-kVp tube voltage, 25% reduced contrast agent volume with advanced iteration algorithm and high tube current modulation achieved radiation dose reduction of 31.7%, as well as better image quality and diagnostic confidence.
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Affiliation(s)
- Min Su Park
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang-si, Gyeonggi-do, Republic of Korea
| | - Hong Il Ha
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang-si, Gyeonggi-do, Republic of Korea
| | - Jhii-Hyun Ahn
- Department of Radiology, Yonsei University Wonju College of Medicine, Wonju Severance Christian Hospital, Wonju, Gangwon-do, Republic of Korea
| | - In Jae Lee
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang-si, Gyeonggi-do, Republic of Korea
| | - Hyun Kyung Lim
- Department of Radiology, Soonchunhyang University Seoul Hospital, Seoul, Republic of Korea
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Borges AP, Antunes C, Caseiro-Alves F. Spectral CT: Current Liver Applications. Diagnostics (Basel) 2023; 13:diagnostics13101673. [PMID: 37238163 DOI: 10.3390/diagnostics13101673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
Using two different energy levels, dual-energy computed tomography (DECT) allows for material differentiation, improves image quality and iodine conspicuity, and allows researchers the opportunity to determine iodine contrast and radiation dose reduction. Several commercialized platforms with different acquisition techniques are constantly being improved. Furthermore, DECT clinical applications and advantages are continually being reported in a wide range of diseases. We aimed to review the current applications of and challenges in using DECT in the treatment of liver diseases. The greater contrast provided by low-energy reconstructed images and the capability of iodine quantification have been mostly valuable for lesion detection and characterization, accurate staging, treatment response assessment, and thrombi characterization. Material decomposition techniques allow for the non-invasive quantification of fat/iron deposition and fibrosis. Reduced image quality with larger body sizes, cross-vendor and scanner variability, and long reconstruction time are among the limitations of DECT. Promising techniques for improving image quality with lower radiation dose include the deep learning imaging reconstruction method and novel spectral photon-counting computed tomography.
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Affiliation(s)
- Ana P Borges
- Medical Imaging Department, Coimbra University Hospitals, 3004-561 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal
- Academic and Clinical Centre of Coimbra, 3000-370 Coimbra, Portugal
| | - Célia Antunes
- Medical Imaging Department, Coimbra University Hospitals, 3004-561 Coimbra, Portugal
- Academic and Clinical Centre of Coimbra, 3000-370 Coimbra, Portugal
| | - Filipe Caseiro-Alves
- Medical Imaging Department, Coimbra University Hospitals, 3004-561 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal
- Academic and Clinical Centre of Coimbra, 3000-370 Coimbra, Portugal
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Inoue A, Uemura R, Takaki K, Sonoda A, Ota S, Nitta N, Batsaikhan B, Takahashi H, Watanabe Y. Clinical impact of low tube voltage computed tomography during hepatic arteriography with low iodine to detect hepatocellular carcinoma before transarterial chemoembolization. Eur J Radiol 2022; 154:110420. [DOI: 10.1016/j.ejrad.2022.110420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 05/31/2022] [Accepted: 06/20/2022] [Indexed: 11/17/2022]
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Yoo J, Lee JM, Yoon JH, Joo I, Lee ES, Jeon SK, Jang S. Comparison of low kVp CT and dual-energy CT for the evaluation of hypervascular hepatocellular carcinoma. Abdom Radiol (NY) 2021; 46:3217-3226. [PMID: 33713160 DOI: 10.1007/s00261-020-02888-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/25/2020] [Accepted: 11/27/2020] [Indexed: 01/19/2023]
Abstract
PURPOSE To compare lesion conspicuity and image quality of arterial phase images obtained from low kVp (90-kVp) and dual-energy (DE) scans for the evaluation of hypervascular hepatocellular carcinoma (HCC). METHODS This retrospective study included 229 patients with HCC who underwent either 90 kVp (n = 106) or DE scan (80- and 150-kVp with a tin filter) (n = 123) during the arterial phase. DE scans were reconstructed into a linearly blended image with a mixed ratio of 0.6 (60% 80kVp and 40% 150 kVp) and post-processed for 40 keV and 50 keV images. The contrast-to-noise ratio (CNR) of HCC to the liver and image noise was measured. Lesion conspicuity, liver parenchymal image quality, and overall image preference were assessed qualitatively by three independent radiologists. RESULTS DE 40 keV images had the highest CNR of HCC, and DE blended images had the lowest image noise among four image sets (p = 0.01 and p < 0.001, respectively). There was no significant difference in mean volume CT dose index and dose-length product between DE and low kVp scan (ps > 0.05). For qualitative analyses, DE blended images had the highest scores for image quality and overall image preference (ps < 0.001). CONCLUSION At an equal radiation dose, DE 40 keV showed higher CNR of HCC and DE blended image showed higher image quality and image preference compared with low kVp CT.
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Affiliation(s)
- Jeongin Yoo
- Department of Radiology, Seoul National University Hospital, Seoul, Korea
| | - Jeong Min Lee
- Department of Radiology, Seoul National University Hospital, Seoul, Korea.
- Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.
- Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Daehak-ro 101, Jongno-gu, Seoul, 03080, Korea.
| | - Jeong Hee Yoon
- Department of Radiology, Seoul National University Hospital, Seoul, Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
| | - Ijin Joo
- Department of Radiology, Seoul National University Hospital, Seoul, Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
| | - Eun Sun Lee
- Department of Radiology, Chung-Ang University Hospital, Seoul, Korea
| | - Sun Kyung Jeon
- Department of Radiology, Seoul National University Hospital, Seoul, Korea
| | - Siwon Jang
- Department of Radiology, Seoul National University Boramae Hospital, Seoul, Korea
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Nam JG, Hong JH, Kim DS, Oh J, Goo JM. Deep learning reconstruction for contrast-enhanced CT of the upper abdomen: similar image quality with lower radiation dose in direct comparison with iterative reconstruction. Eur Radiol 2021; 31:5533-5543. [PMID: 33555354 DOI: 10.1007/s00330-021-07712-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 12/23/2020] [Accepted: 01/21/2021] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To evaluate the effect of a commercial deep learning algorithm on the image quality of chest CT, focusing on the upper abdomen. METHODS One hundred consecutive patients who simultaneously underwent contrast-enhanced chest and abdominal CT were collected. The radiation dose was optimized for each scan (mean CTDIvol: chest CT, 3.19 ± 1.53 mGy; abdominal CT, 7.10 ± 1.88 mGy). Three image sets were collected: chest CT reconstructed with an adaptive statistical iterative reconstruction (ASiR-CHT; 50% blending), chest CT with a deep learning algorithm (DLIR-CHT), and abdominal CT with ASiR (ASiR-ABD; 40% blending). Afterwards, the images covering the upper abdomen were extracted, and image noise, the signal-to-noise ratio (SNR), and the contrast-to-noise ratio (CNR) were measured. For subjective evaluation, three radiologists independently assessed noise, spatial resolution, presence of artifacts, and overall image quality. Additionally, readers selected the most preferable reconstruction technique among three image sets for each case. RESULTS The average measured noise for DLIR-CHT, ASiR-CHT, and ASiR-ABD was 8.01 ± 2.81, 14.8 ± 2.56, and 12.3 ± 2.28, respectively (p < .001). Deep learning-based image reconstruction (DLIR) also showed the best SNR and CNR (p < .001). However, in the subjective analysis, ASiR-ABD showed less subjective noise than DLIR (2.94 ± 0.23 vs. 2.87 ± 0.26; p < .001), while DLIR showed better spatial resolution (2.60 ± 0.34 vs. 2.44 ± 0.31; p = .02). ASiR-ABD showed a better overall image quality (p = .001), but two of the three readers preferred DLIR more frequently. CONCLUSION With < 50% of the radiation dose, DLIR chest CT showed comparable image quality in the upper abdomen to that of dedicated abdominal CT and was preferred by most readers. KEY POINTS • With < 50% radiation dose, a deep learning algorithm applied to contrast-enhanced chest CT exhibited better image noise and signal-to-noise ratio than standard abdominal CT with the ASiR technique. • Pooled readers mostly preferred deep learning algorithm-reconstructed contrast-enhanced chest CT reconstructed using a standard ASiR-reconstructed abdominal CT. • Reconstruction algorithm-induced distortion artifacts were more frequently observed on deep learning algorithm-reconstructed images, but diagnostic difficulty was reported in only 0.3% of cases.
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Affiliation(s)
- Ju Gang Nam
- Department of Radiology, Seoul National University Hospital and College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, 101 Daehak-ro, Jongno-gu, 03080, Seoul, Republic of Korea
| | - Jung Hee Hong
- Department of Radiology, Seoul National University Hospital and College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, 101 Daehak-ro, Jongno-gu, 03080, Seoul, Republic of Korea
| | - Da Som Kim
- Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan, 47392, Republic of Korea
| | - Jiseon Oh
- Department of Radiology, Seoul National University Hospital and College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, 101 Daehak-ro, Jongno-gu, 03080, Seoul, Republic of Korea
| | - Jin Mo Goo
- Department of Radiology, Seoul National University Hospital and College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, 101 Daehak-ro, Jongno-gu, 03080, Seoul, Republic of Korea. .,Cancer Research Institute, Seoul National University College of Medicine, 03080, Seoul, Republic of Korea.
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High-pitch, 120 kVp/30 mAs, low-dose dual-source chest CT with iterative reconstruction: Prospective evaluation of radiation dose reduction and image quality compared with those of standard-pitch low-dose chest CT in healthy adult volunteers. PLoS One 2019; 14:e0211097. [PMID: 30677082 PMCID: PMC6345490 DOI: 10.1371/journal.pone.0211097] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 01/08/2019] [Indexed: 01/08/2023] Open
Abstract
PURPOSE Objective of this study was to evaluate the effectiveness of the iterative reconstruction of high-pitch dual-source chest CT (IR-HP-CT) scanned with low radiation exposure compared with low dose chest CT (LDCT). MATERIALS AND METHODS This study was approved by the institutional review board. Thirty healthy adult volunteers (mean age 44 years) were enrolled in this study. All volunteers underwent both IR-HP-CT and LDCT. IR-HP-CT was scanned with 120 kVp tube voltage, 30 mAs tube current and pitch 3.2 and reconstructed with sinogram affirmed iterative reconstruction. LDCT was scanned with 120 kVp tube voltage, 40 mAs tube current and pitch 0.8 and reconstructed with B50 filtered back projection. Image noise, and signal to noise ratio (SNR) of the infraspinatus muscle, subcutaneous fat and lung parenchyma were calculated. Cardiac motion artifact, overall image quality and artifacts was rated by two blinded readers using 4-point scale. The dose-length product (DLP) (mGy∙cm) were obtained from each CT dosimetry table. Scan length was calculated from the DLP results. The DLP parameter was a metric of radiation output, not of patient dose. Size-specific dose estimation (SSDE, mGy) was calculated using the sum of the anteroposterior and lateral dimensions and effective radiation dose (ED, mSv) were calculated using CT dosimetry index. RESULTS Approximately, mean 40% of SSDE (2.1 ± 0.2 mGy vs. 3.5 ± 0.3 mGy) and 34% of ED (1.0 ± 0.1 mSv vs. 1.5 ± 0.1 mSv) was reduced in IR-HP-CT compared to LDCT (P < 0.0001). Image noise was reduced in the IR-HP-CT (16.8 ± 2.8 vs. 19.8 ± 3.4, P = 0.0001). SNR of lung and aorta of IR-HP-CT showed better results compared with that of LDCT (22.2 ± 5.9 vs. 33.0 ± 7.8, 1.9 ± 0.4 vs 1.1 ± 0.3, P < 0.0001). The score of cardiac pulsation artifacts were significantly reduced on IR-HP-CT (3.8 ± 0.4, 95% confidence interval, 3.7‒4.0) compared with LDCT (1.6 ± 0.6, 95% confidence interval, 1.3‒1.8) (P < 0.0001). SNR of muscle and fat, beam hardening artifact and overall subjective image quality of the mediastinum, lung and chest wall were comparable on both scans (P ≥ 0.05). CONCLUSION IR-HP-CT with 120 kVp and 30 mAs tube setting in addition to an iterative reconstruction reduced cardiac motion artifact and radiation exposure while representing similar image quality compared with LDCT.
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Nakamoto A, Yamamoto K, Sakane M, Nakai G, Higashiyama A, Juri H, Yoshikawa S, Narumi Y. Reduction of the radiation dose and the amount of contrast material in hepatic dynamic CT using low tube voltage and adaptive iterative dose reduction 3-dimensional. Medicine (Baltimore) 2018; 97:e11857. [PMID: 30142778 PMCID: PMC6113013 DOI: 10.1097/md.0000000000011857] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The purpose of this study was to prospectively evaluate the image quality and the diagnostic ability of low tube voltage and reduced contrast material dose hepatic dynamic computed tomography (CT) reconstructed with adaptive iterative dose reduction 3-dimensional (AIDR 3D).Eighty-nine patients underwent hepatic dynamic CT using one of the 2 protocols: tube voltage of 120 kVp, contrast dose of 600 mgI/kg, and filtered back projection in Protocol A (n = 46), and tube voltage of 100 kVp, contrast dose of 500 mgI/kg, and AIDR 3D in Protocol B (n = 43). The volume CT dose index (CTDIvol) and size-specific dose estimates (SSDEs) were compared between the 2 groups. Objective image noise and tumor to liver contrast-to-noise ratio (CNR) were also compared. Three radiologists independently reviewed image quality. The jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis was performed to compare diagnostic performance.The mean CTDIvol and SSDE of Protocol B (14.3 and 20.2, respectively) were significantly lower than those of Protocol A (22.1 and 31.4, P < .001). There were no significant differences in either objective image noise or CNR. In the qualitative analysis, 2 readers assigned significant lower scores to images of Protocol B for at least one of the 3 phases regarding overall image quality (P < .05). There was no significant difference in the JAFROC1 figure of merit between protocols.Low tube voltage CT with AIDR 3D yielded a reduction in radiation dose and in the amount of contrast material while maintaining diagnostic performance.
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Affiliation(s)
- Atsushi Nakamoto
- Department of Radiology, Osaka Medical College, Takatsuki
- Department of Radiology, Osaka University Graduate School of Medicine, Suita
| | | | - Makoto Sakane
- Department of Radiology, Osaka Medical College, Takatsuki
| | - Go Nakai
- Department of Radiology, Osaka Medical College, Takatsuki
| | | | - Hiroshi Juri
- Department of Radiology, Osaka Medical College, Takatsuki
| | - Shushi Yoshikawa
- Central Radiology Department, Osaka Medical College Hospital, Takatsuki, Osaka, Japan
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Pang T, Liu ZD, Deng K, Zhang CQ, Wang GL. Preliminary application of multiple parameters spectral CT in the diagnosis of ovarian cancer. Medicine (Baltimore) 2017; 96:e7786. [PMID: 28796078 PMCID: PMC5556244 DOI: 10.1097/md.0000000000007786] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The aim of the study was to evaluate the effectiveness of spectral CT in the diagnosis of ovarian cancer. We retrospectively analyzed the data of 22 patients with spectral CT enhanced scan. The patients were divided into 2 groups: ovarian cancer group (n = 11) and benign tumor group (n = 11), according to the pathologic results. CT values at 40 keV, iodine concentration (IC), water concentration (WC) and spectral curve slope (λHU) of arterial phase and venous phase in the tumors of 2 groups were measured with gemstone spectral imaging (GSI) post-processing software. The independent samples t test was used to compare these multiple parameters above between 2 groups. For the parameters which showed statistically different, the ROC curves were further generated to calculate their diagnostic effectiveness respectively. According to the results, CT values at 40 keV, IC and λHU measured in arterial and venous phases were higher in ovarian cancer group than those in benign tumor group. There were significant differences between these 2 groups (P < 0.05). While WC had no significant difference in these 2 groups (P > 0.05). CT values at 40 keV, IC and λHU had high effectiveness to the diagnosis of ovarian cancer according to ROC curves. The optimal parameter among them was IC in arterial phase with AUC of 0.90. Using 10.92 (100 ug/cm3) as a threshold value, the sensitivity and specificity for diagnosis were 88.9% and 94.7%. Thus, we concluded that spectral CT with multiple parameters was valuable in the diagnosis of ovarian cancer.
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Jiang J, Wang K, Xu Y, Liu J, Luo J, Tao X, Wang X. Preoperative Assessment of Hepatocellular Carcinoma with Split-Bolus Combined Phase Contrast-Enhanced Computed Tomography. Med Sci Monit 2017; 23:1834-1841. [PMID: 28412761 PMCID: PMC5402837 DOI: 10.12659/msm.904129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background The aim of this study was to investigate the feasibility of a split-bolus combined phase contrast-enhanced computed tomography protocol in evaluation of liver vasculature in hepatocellular carcinoma (HCC) patients for the purpose of surgery guidance. Material/Methods Two groups of patients were recruited for the study: 24 consecutive cases of HCC who underwent multiphasic CT examination, and 22 consecutive cases who afterwards underwent split-bolus combined phase CT examination. The multiphasic protocol included an unenhanced scan and 3 image acquisitions after contrast injection. The injection of contrast medium was 440 mgI/kg in a single bolus. The split-bolus combined phase protocol included unenhanced scan and combined phase. The injection of contrast medium was 440 mgI/kg for the first bolus and 220 mgI/kg for the second bolus. The vascular delineation was evaluated with Likert scales. The CT values were measured, and the contrast-to-noise ratio (CNR) was calculated. We also compared the effective radiation dose (ED) of the 2 protocols. Results All mean CT values were significantly higher in the split-bolus protocol than in the multiphasic protocol (all P<.05), except for the hepatic vein (P>.05). The ED was significantly lower in the split-bolus protocol, corresponding to a dose reduction of 66% compared to the multiphasic protocol (P<.05). The scores of the branches of the hepatic vein in the split-bolus protocol were not lower than those in the multiphasic protocol. Conclusions For the preoperative HCC patients, the split-bolus combined phase CT examination meets the diagnostic requirement of surgical planning, with approximately 60% reduction in the radiation dose.
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Affiliation(s)
- Jian Jiang
- Department of Radiology, Peking University First Hospital, Beijing, China (mainland)
| | - Ke Wang
- Department of Radiology, Peking University First Hospital, Beijing, China (mainland)
| | - Yufeng Xu
- Department of Radiology, Peking University First Hospital, Beijing, China (mainland)
| | - Jianxin Liu
- Department of Radiology, Peking University First Hospital, Beijing, China (mainland)
| | - Jingjing Luo
- Department of Radiology, Peking University First Hospital, Beijing, China (mainland)
| | - Xin Tao
- Department of Radiology, Peking University First Hospital, Beijing, China (mainland)
| | - Xiaoying Wang
- Department of Radiology, Peking University First Hospital, Beijing, China (mainland)
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Zhao Y, Suo H, Wu Y, Zuo Z, Zhao S, Cheng S. Noise indices adjusted to body mass index and an iterative reconstruction algorithm maintain image quality on low-dose contrast-enhanced liver CT. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2017; 25:XST16222. [PMID: 28387698 DOI: 10.3233/xst-16222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
OBJECTIVES Since body mass index (BMI) affects medical imaging quality or noise due to penetration of the radiation through bodies with varying sizes, this study aims to investigate and determine the optimal BMI-adjusted noise index (NI) setting on the contrast-enhanced liver CT scans obtained using 3D Smart mA technology with adaptive statistical iterative reconstruction (ASIR 2.0) algorithm. MATERIALS AND METHODS A total of 320 patients who had contrast-enhanced liver CT scans were divided into two equal-sized groups: A (18.5 kg/m2≤BMI<24.9 kg/m2) and B (24.9 kg/m2 ≤ BMI ≤34.9 kg/m2). The two groups were randomly divided into four subgroups with an NI of 11, 13, 15, and 17. All images were reconstructed with 50% ASIR 2.0. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated after the late arterial, portal venous, and equilibrium phases were completed. Images were evaluated by two radiologists using a subjective 0 -5 scale. Mean CT dose index of volume, dose-length product, and effective dose (ED) were calculated and compared using one-way ANOVA. RESULTS In group A, the best-quality images obtained at the lowest ED were scanned at an NI of 15 in the late arterial phase, and at an NI of 17 in the portal venous and equilibrium phases. In group B, the best results were obtained at an NI of 13 in the late arterial phase, and at an NI of 15 in the portal venous and equilibrium phases. CONCLUSION Adjusting NI and iterative reconstruction algorithm based on body mass index can help improve image quality on contrast-enhanced liver CT scans, even at low radiation dose.
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Affiliation(s)
- Yongxia Zhao
- The Affiliated Hospital of Hebei University, Baoding, Hebei Province, China
| | - Hongna Suo
- Medicine School of Hebei University, Baoding, Hebei Province, China
| | - Yanmin Wu
- The Affiliated Hospital of Hebei University, Baoding, Hebei Province, China
| | - Ziwei Zuo
- The Affiliated Hospital of Hebei University, Baoding, Hebei Province, China
| | - Sisi Zhao
- The Affiliated Hospital of Hebei University, Baoding, Hebei Province, China
| | - Shujie Cheng
- The Affiliated Hospital of Hebei University, Baoding, Hebei Province, China
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Altenbernd J, Wetter A, Forsting M, Umutlu L. Dual-energy CT of liver metastases in patients with uveal melanoma. Eur J Radiol Open 2016; 3:254-258. [PMID: 27830163 PMCID: PMC5094679 DOI: 10.1016/j.ejro.2016.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/22/2016] [Indexed: 01/08/2023] Open
Abstract
Objective To investigate the value of different kVp images of dual-energy CT (DECT) for the detection of liver metastases. Methods 20 Patients with uveal melanoma were investigated with DECT of the liver. In each patient contrast-enhanced DECT imaging with arterial delay was performed. Number and size of metastases were documented on arterial phase 80-kVp images, virtual 120-kVp images and following angiographic images (DSA) as part of hepatic chemoperfusion. Attenuation of metastases and several anatomic regions, subjective (image noise, image quality) and objective (SNR, CNR) parameters were documented. Results The mean number of liver metastases detected was significant higher on 80-kVp images than on virtual 120-kVp/DSA images (5.6 ± 2.1 vs. 4.1 ± 1.8/4.3 ± 1.6); (p < 0.001). All lesions sizes were significant better detected with 80 kVp images than with virtual 120 kVp and DSA-Images (80 kVp vs. 120 kVp: <10 mm: 34 vs. 19, p < 0.05; 10–20 mm:, 33 vs. 25, p < 0.05; >20 mm: 56 vs. 42, p < 0.05/80 kVp vs. DSA: <10 mm: 34 vs. 18 p < 0.05; 10–20 mm: 33 vs. 24, p < 0.05; >20 mm: 56 vs. 41, p < 0.05). Number of detected small lesions <10 mm with 120 kVp compared to DSA-images were significant higher (19 vs. 13; p < 0.05), lesions 10–20 mm and >20 mm were measured statistically equally. Noise, SNR and CNR of 80 kVp images were higher compared to 120 kVp images. Image quality of 120 kVp images was higher compared to 80 kVp images. Conclusion Low-kVp images of DECT datasets are more sensitive in detecting liver metastases of patients with uveal melanoma than virtual 120 kVp- and DSA images.
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Affiliation(s)
- Jens Altenbernd
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Germany
| | - Axel Wetter
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Germany
| | - Michael Forsting
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Germany
| | - Lale Umutlu
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Germany
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Optimizing CT technique to reduce radiation dose: effect of changes in kVp, iterative reconstruction, and noise index on dose and noise in a human cadaver. Radiol Phys Technol 2016; 10:180-188. [DOI: 10.1007/s12194-016-0382-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/21/2016] [Accepted: 09/25/2016] [Indexed: 10/20/2022]
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Comparison of Knowledge-based Iterative Model Reconstruction and Hybrid Reconstruction Techniques for Liver CT Evaluation of Hypervascular Hepatocellular Carcinoma. J Comput Assist Tomogr 2016; 40:863-871. [PMID: 27331929 DOI: 10.1097/rct.0000000000000455] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Xiao H, Liu Y, Tan H, Liang P, Wang B, Su L, Wang S, Gao J. A pilot study using low-dose Spectral CT and ASIR (Adaptive Statistical Iterative Reconstruction) algorithm to diagnose solitary pulmonary nodules. BMC Med Imaging 2015; 15:54. [PMID: 26576676 PMCID: PMC4647278 DOI: 10.1186/s12880-015-0096-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 10/25/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Lung cancer is the most common cancer which has the highest mortality rate. With the development of computed tomography (CT) techniques, the case detection rates of solitary pulmonary nodules (SPN) has constantly increased and the diagnosis accuracy of SPN has remained a hot topic in clinical and imaging diagnosis. The aim of this study was to evaluate the combination of low-dose spectral CT and ASIR (Adaptive Statistical Iterative Reconstruction) algorithm in the diagnosis of solitary pulmonary nodules (SPN). METHODS 62 patients with SPN (42 cases of benign SPN and 20 cases of malignant SPN, pathology confirmed) were scanned by spectral CT with a dual-phase contrast-enhanced method. The iodine and water concentration (IC and WC) of the lesion and the artery in the image that had the same density were measured by the GSI (Gemstone Spectral Imaging) software. The normalized iodine and water concentration (NIC and NWC) of the lesion and the normalized iodine and water concentration difference (ICD and WCD) between the arterial and venous phases (AP and VP) were also calculated. The spectral HU (Hounsfield Unit ) curve was divided into 3 sections based on the energy (40-70, 70-100 and 100-140 keV) and the slopes (λHU) in both phases were calculated. The ICAP, ICVP, WCAP and WCVP, NIC and NWC, and the λHU in benign and malignant SPN were compared by independent sample t-test. RESULTS The iodine related parameters (ICAP, ICVP, NICAP, NICVP, and the ICD) of malignant SPN were significantly higher than that of benign SPN (t = 3.310, 1.330, 2.388, 1.669 and 3.251, respectively, P <0.05). The 3 λHU values of venous phase in malignant SPN were higher than that of benign SPN (t = 3.803, 2.846 and 3.205, P <0.05). The difference of water related parameters (WCAP, WCVP, NWCAP, NWCVP and WCD) between malignant and benign SPN were not significant (t = 0.666, 0.257, 0.104, 0.550 and 0.585, P > 0.05). CONCLUSIONS The iodine related parameters and the slope of spectral curve are useful markers to distinguish the benign from the malignant lung diseases, and its application is extremely feasible in clinical applications.
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Affiliation(s)
- Huijuan Xiao
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No.1, East Jianshe Road, Zhengzhou, Henan Province, 450052, China.
| | - Yihe Liu
- The No.7 People's Hospital of Zhengzhou, 17 Jingnan 5th Road, Zhengzhou Economic and Technological Development Zone, Zhengzhou, Henan Province, 450000, China.
| | - Hongna Tan
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No.1, East Jianshe Road, Zhengzhou, Henan Province, 450052, China.
| | - Pan Liang
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No.1, East Jianshe Road, Zhengzhou, Henan Province, 450052, China.
| | - Bo Wang
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No.1, East Jianshe Road, Zhengzhou, Henan Province, 450052, China.
| | - Lei Su
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No.1, East Jianshe Road, Zhengzhou, Henan Province, 450052, China.
| | - Suya Wang
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No.1, East Jianshe Road, Zhengzhou, Henan Province, 450052, China.
| | - Jianbo Gao
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No.1, East Jianshe Road, Zhengzhou, Henan Province, 450052, China.
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Seyal AR, Arslanoglu A, Abboud SF, Sahin A, Horowitz JM, Yaghmai V. CT of the Abdomen with Reduced Tube Voltage in Adults: A Practical Approach. Radiographics 2015; 35:1922-39. [PMID: 26473536 DOI: 10.1148/rg.2015150048] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent innovations in computed tomographic (CT) hardware and software have allowed implementation of low tube voltage imaging into everyday CT scanning protocols in adults. CT at a low tube voltage setting has many benefits, including (a) radiation dose reduction, which is crucial in young patients and those with chronic medical conditions undergoing serial CT examinations for disease management; and (b) higher contrast enhancement. For the latter, increased attenuation of iodinated contrast material improves the evaluation of hypervascular lesions, vascular structures, intestinal mucosa in patients with bowel disease, and CT urographic images. Additionally, the higher contrast enhancement may provide diagnostic images in patients with renal dysfunction receiving a reduced contrast material load and in patients with suboptimal peripheral intravenous access who require a lower contrast material injection rate. One limitation is that noisier images affect image quality at a low tube voltage setting. The development of denoising algorithms such as iterative reconstruction has made it possible to perform CT at a low tube voltage setting without compromising diagnostic confidence. Other potential pitfalls of low tube voltage CT include (a) photon starvation artifact in larger patients, (b) accentuation of streak artifacts, and (c) alteration of the CT attenuation value, which may affect evaluation of lesions on the basis of conventional enhancement thresholds. CT of the abdomen with a low tube voltage setting is an excellent radiation reduction technique when properly applied to imaging of select patients in the appropriate clinical setting.
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Affiliation(s)
- Adeel R Seyal
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Atilla Arslanoglu
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Samir F Abboud
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Azize Sahin
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Jeanne M Horowitz
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Vahid Yaghmai
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
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Geyer LL, Schoepf UJ, Meinel FG, Nance JW, Bastarrika G, Leipsic JA, Paul NS, Rengo M, Laghi A, De Cecco CN. State of the Art: Iterative CT Reconstruction Techniques. Radiology 2015. [PMID: 26203706 DOI: 10.1148/radiol.2015132766] [Citation(s) in RCA: 398] [Impact Index Per Article: 44.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Lucas L Geyer
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - U Joseph Schoepf
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Felix G Meinel
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - John W Nance
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Gorka Bastarrika
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Jonathon A Leipsic
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Narinder S Paul
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Marco Rengo
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Andrea Laghi
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Carlo N De Cecco
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
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CT Liver Imaging: What is New? CURRENT RADIOLOGY REPORTS 2015. [DOI: 10.1007/s40134-015-0088-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Song JS, Choi EJ, Kim EY, Kwak HS, Han YM. Attenuation-based automatic kilovoltage selection and sinogram-affirmed iterative reconstruction: effects on radiation exposure and image quality of portal-phase liver CT. Korean J Radiol 2015; 16:69-79. [PMID: 25598675 PMCID: PMC4296279 DOI: 10.3348/kjr.2015.16.1.69] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 10/19/2014] [Indexed: 11/20/2022] Open
Abstract
Objective To compare the radiation dose and image quality between standard-dose CT and a low-dose CT obtained with the combined use of an attenuation-based automatic kilovoltage (kV) selection tool (CARE kV) and sinogram-affirmed iterative reconstruction (SAFIRE) for contrast-enhanced CT examination of the liver. Materials and Methods We retrospectively reviewed 67 patients with chronic liver disease in whom both, standard-dose CT with 64-slice multidetector-row CT (MDCT) (protocol A), and low-dose CT with 128-slice MDCT using CARE kV and SAFIRE (protocol B) were performed. Images from protocol B during the portal phase were reconstructed using either filtered back projection or SAFIRE with 5 different iterative reconstruction (IR) strengths. We performed qualitative and quantitative analyses to select the appropriate IR strength. Reconstructed images were then qualitatively and quantitatively compared with protocol A images. Results Qualitative and quantitative analysis of protocol B demonstrated that SAFIRE level 2 (S2) was most appropriate in our study. Qualitative and quantitative analysis comparing S2 images from protocol B with images from protocol A, showed overall good diagnostic confidence of S2 images despite a significant radiation dose reduction (47% dose reduction, p < 0.001). Conclusion Combined use of CARE kV and SAFIRE allowed significant reduction in radiation exposure while maintaining image quality in contrast-enhanced liver CT.
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Affiliation(s)
- Ji Soo Song
- Department of Radiology, Chonbuk National University Medical School and Hospital, Biomedical Research Institute of Chonbuk National University Hospital, Jeonju 561-712, Korea
| | - Eun Jung Choi
- Department of Radiology, Chonbuk National University Medical School and Hospital, Biomedical Research Institute of Chonbuk National University Hospital, Jeonju 561-712, Korea
| | - Eun Young Kim
- Department of Radiology, Chonbuk National University Medical School and Hospital, Biomedical Research Institute of Chonbuk National University Hospital, Jeonju 561-712, Korea
| | - Hyo Sung Kwak
- Department of Radiology, Chonbuk National University Medical School and Hospital, Biomedical Research Institute of Chonbuk National University Hospital, Jeonju 561-712, Korea
| | - Young Min Han
- Department of Radiology, Chonbuk National University Medical School and Hospital, Biomedical Research Institute of Chonbuk National University Hospital, Jeonju 561-712, Korea
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Lee JM, Park JW, Choi BI. 2014 KLCSG-NCC Korea Practice Guidelines for the management of hepatocellular carcinoma: HCC diagnostic algorithm. Dig Dis 2014; 32:764-77. [PMID: 25376295 DOI: 10.1159/000368020] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Hepatocellular carcinoma (HCC) is the fifth most commonly occurring cancer in Korea and typically has a poor prognosis with a 5-year survival rate of only 28.6%. Therefore, it is of paramount importance to achieve the earliest possible diagnosis of HCC and to recommend the most up-to-date optimal treatment strategy in order to increase the survival rate of patients who develop this disease. After the establishment of the Korean Liver Cancer Study Group (KLCSG) and the National Cancer Center (NCC), Korea jointly produced for the first time the Clinical Practice Guidelines for HCC in 2003, revised them in 2009, and published the newest revision of the guidelines in 2014, including changes in the diagnostic criteria of HCC and incorporating the most recent medical advances over the past 5 years. In this review, we will address the noninvasive diagnostic criteria and diagnostic algorithm of HCC included in the newly established KLCSG-NCC guidelines in 2014, and review the differences in the criteria for a diagnosis of HCC between the KLCSG-NCC guidelines and the most recent imaging guidelines endorsed by the European Organisation for Research and Treatment of Cancer (EORTC), the Liver Imaging Reporting and Data System (LI-RADS), the Organ Procurement and Transplantation Network (OPTN) system, the Asian Pacific Association for the Study of the Liver (APASL) and the Japan Society of Hepatology (JSH).
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Affiliation(s)
- Jeong Min Lee
- Department of Radiology, Seoul National University Hospital, Seoul, Korea
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Dual-Energy Liver CT: Effect of Monochromatic Imaging on Lesion Detection, Conspicuity, and Contrast-to-Noise Ratio of Hypervascular Lesions on Late Arterial Phase. AJR Am J Roentgenol 2014; 203:601-6. [DOI: 10.2214/ajr.13.11337] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Ben-David E, Cohen JE, Nahum Goldberg S, Sosna J, Levinson R, Leichter IS, Gomori JM. Significance of enhanced cerebral gray-white matter contrast at 80 kVp compared to conventional 120 kVp CT scan in the evaluation of acute stroke. J Clin Neurosci 2014; 21:1591-4. [PMID: 24768150 DOI: 10.1016/j.jocn.2014.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 03/16/2014] [Indexed: 11/18/2022]
Abstract
We aimed to determine whether 80 kVp conventional nonenhanced head CT scans have better gray-white matter contrast than standard 120 kVp scans performed on the same patients. Thirty head CT scans acquired at 80 kVp (CT dose index [CTDI]vol 46) were compared to prior studies in the same patients performed at 120 kVp (CTDIvol 59). Signal (Hounsfield units [HU]), noise (sd HU), and contrast-to-noise ratio per dose (CNRD) were assessed in multiple cerebral gray and white matter regions of interest. A noise correction factor was used to compensate for scanning at different CTDIvol values. Average gray matter signal at 80 kVp and 120 kVP was 33.9 ± 3.5 HU and 29 ± 4.6 HU, respectively (p<0.0001); the averages for white matter were 22.5 ± 3.1 HU and 21.6 ± 4.6 HU, respectively (p=0.11). Corrected noise was 3 ± 0.6 and 2.7 ± 0.6, respectively, for gray matter (p=0.0001), and 2.8 ± 0.6 and 2.6 ± 0.5, respectively, for white matter (p=0.00001). The gray-white matter CNRD was 4.0 ± 1.2 at 80 kVp and 2.8 ± 1 at 120 kVp (p<0.00001). Cerebral gray-white matter CNRD is increased by 40% at 80 kVp compared to conventional 120 kVp CT scans. These findings justify further clinical evaluation in the acute stroke setting.
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Affiliation(s)
- Eliel Ben-David
- Department of Radiology, Hadassah-Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel
| | - Jose E Cohen
- Department of Radiology, Hadassah-Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel; Department of Neurosurgery, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - S Nahum Goldberg
- Department of Radiology, Hadassah-Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel
| | - Jacob Sosna
- Department of Radiology, Hadassah-Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel; Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | | | - Isaac S Leichter
- Department of Radiology, Hadassah-Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel
| | - John M Gomori
- Department of Radiology, Hadassah-Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel.
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Preliminary application of high-definition computed tomographic Gemstone Spectral Imaging in lung cancer. J Comput Assist Tomogr 2014; 38:77-81. [PMID: 24378884 DOI: 10.1097/rct.0b013e3182a21633] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate the feasibility of multiparameter quantitative measurement lung cancer by Gemstone Spectral Imaging (GSI) high-definition computed tomography. MATERIALS AND METHODS Seventy-seven patients who were found to have a lung mass or a nodule by CT plain scan for the first time received chest contrast CT scan with GSI mode on high-definition computed tomography. The GSI viewer was used to display the spectral curve, iodine-based images, water-based images, and 101 sets of monochromatic images of a selected region of interest from the relative homogeneous area of the mass or nodule. Iodine concentration, water concentration, spectral curve slope, and CT values at 40 keV of the region of interest were measured. Finally, 68 eligible patients were divided into a pneumonia group (n = 24) and a malignant tumor group (n = 44, including squamous carcinoma, n = 29, and adenocarcinoma, n = 15). RESULTS Significant differences existed in iodine concentration (t = 6.459), spectral curve slope (t = 6.276), and CT values at 40 keV (t = 6.698) between the pneumonia group and the malignant tumor group (P < 0.05), as well as between squamous carcinoma and adenocarcinoma (t = 6.494, 5.634, 6.091, respectively, P < 0.05), whereas water concentrations were found to have no difference between the 2 groups (t = 0.082, P > 0.05) and between the 2 types of malignant tumors (t = 1.234, P > 0.05). CONCLUSIONS High-definition computed tomographic GSI technique might be helpful to differentiate lung cancer from lung benign lesions by providing qualitative and quantitative information.
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Recent developments of dual-energy CT in oncology. Eur Radiol 2014; 24:930-9. [DOI: 10.1007/s00330-013-3087-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 11/14/2013] [Accepted: 12/06/2013] [Indexed: 12/27/2022]
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Jung SI, Park HS, Kim YJ, Jeon HJ. Multidetector computed tomography for the assessment of adnexal mass: is unenhanced CT scan necessary? Korean J Radiol 2014; 15:72-9. [PMID: 24497795 PMCID: PMC3909865 DOI: 10.3348/kjr.2014.15.1.72] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 09/16/2013] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To compare the diagnostic performance and radiation dose between contrast-enhanced CT (ECT) alone, and combined unenhanced and contrast-enhanced CT (UE + ECT) for the assessment of adnexal mass. MATERIALS AND METHODS This retrospective study was approved by the Institutional Review Board. A total of 146 consecutive patients (mean age, 41.1 years) who underwent preoperative unenhanced and contrast-enhanced multidetector CT of the pelvis and had adnexal masses found at surgery were included. Two readers independently evaluated the likelihood of adnexal malignancy on a 5-point scale on two different imaging datasets (ECT alone and UE + ECT). The area under the receiver operating characteristic curve (AUC) was used to evaluate diagnostic performance. Radiation dose to patients was calculated by the volume CT dose index (CTDIvol) and the dose length products (DLP) on each dataset. RESULTS Of the total 178 adnexal masses, 133 masses were benign and 45 masses were malignant. For both readers, there is no significant difference of AUC values between ECT alone and UE + ECT for the detection of adnexal malignancy (reader 1, 0.93 vs. 0.95; reader 2, 0.92 vs. 0.91) (p > 0.05). The mean CTDIvol (12.6 ± 2.2 mGy) and DLP (641.2 ± 137.2 mGy) of ECT alone was significantly lower than the mean CTDIvol (21.5 ± 2.7 mGy) and DLP (923.6 ± 158.8 mGy) of UE + ECT (p < 0.0001). CONCLUSION The use of unenhanced CT scan in addition to contrast-enhanced CT scan does not improve the detection of adnexal malignancy, but increases radiation exposure.
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Affiliation(s)
- Sung Il Jung
- Department of Radiology, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul 143-729, Korea
| | - Hee Sun Park
- Department of Radiology, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul 143-729, Korea
| | - Young Jun Kim
- Department of Radiology, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul 143-729, Korea
| | - Hae Jeong Jeon
- Department of Radiology, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul 143-729, Korea
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Liver Computed Tomography With Low Tube Voltage and Model-Based Iterative Reconstruction Algorithm for Hepatic Vessel Evaluation in Living Liver Donor Candidates. J Comput Assist Tomogr 2014; 38:367-75. [DOI: 10.1097/rct.0b013e3182ab6cc0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Can Sinogram-Affirmed Iterative Reconstruction Improve the Detection of Small Hypervascular Liver Nodules With Dual-Energy CT? J Comput Assist Tomogr 2014; 38:693-9. [DOI: 10.1097/rct.0000000000000105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Shin HJ, Chung YE, Lee YH, Choi JY, Park MS, Kim MJ, Kim KW. Radiation dose reduction via sinogram affirmed iterative reconstruction and automatic tube voltage modulation (CARE kV) in abdominal CT. Korean J Radiol 2013; 14:886-93. [PMID: 24265563 PMCID: PMC3835635 DOI: 10.3348/kjr.2013.14.6.886] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 08/01/2013] [Indexed: 12/26/2022] Open
Abstract
Objective To evaluate the feasibility of sinogram-affirmed iterative reconstruction (SAFIRE) and automated kV modulation (CARE kV) in reducing radiation dose without increasing image noise for abdominal CT examination. Materials and Methods This retrospective study included 77 patients who received CT imaging with an application of CARE kV with or without SAFIRE and who had comparable previous CT images obtained without CARE kV or SAFIRE, using the standard dose (i.e., reference mAs of 240) on an identical CT scanner and reconstructed with filtered back projection (FBP) within 1 year. Patients were divided into two groups: group A (33 patients, CT scanned with CARE kV); and group B (44 patients, scanned after reducing the reference mAs from 240 to 170 and applying both CARE kV and SAFIRE). CT number, image noise for four organs and radiation dose were compared among the two groups. Results Image noise increased after CARE kV application (p < 0.001) and significantly decreased as SAFIRE strength increased (p < 0.001). Image noise with reduced-mAs scan (170 mAs) in group B became similar to that of standard-dose FBP images after applying CARE kV and SAFIRE strengths of 3 or 4 when measured in the aorta, liver or muscle (p ≥ 0.108). Effective doses decreased by 19.4% and 41.3% for groups A and B, respectively (all, p < 0.001) after application of CARE kV with or without SAFIRE. Conclusion Combining CARE kV, reduction of mAs from 240 to 170 mAs and noise reduction by applying SAFIRE strength 3 or 4 reduced the radiation dose by 41.3% without increasing image noise compared with the standard-dose FBP images.
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Affiliation(s)
- Hyun Joo Shin
- Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul 120-752, Korea
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Bernstine H, Sopov V, Yefremov N, Nidam M, Gabbai M, Sosna J, Groshar D. Comparison of 80 and 120 kVp contrast-enhanced CT for attenuation correction in PET/CT, using quantitative analysis and reporter assessment of PET image quality. Clin Radiol 2013; 69:e17-24. [PMID: 24156801 DOI: 10.1016/j.crad.2013.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 07/24/2013] [Accepted: 08/06/2013] [Indexed: 12/13/2022]
Abstract
AIM To determine the effect of low tube voltage on positron-emission tomography (PET) image quality, quantitative analysis, and radiation dose in a combined PET/computed tomography (CT) study in patients with normal body mass index (BMI). MATERIALS AND METHODS One hundred and twenty-nine examinations performed in 46 patients (mean age 57 years), who had at least two separate studies were retrospectively evaluated; at least one with 120 kVp and one with 80 kVp. Three independent readers reviewed all PET images and graded the image quality. PET signal and noise were recorded on the liver, spleen, fat, bone marrow, and aorta. CT dose index (CTDI) and the dose-length product (DLP) were used for CT radiation dose estimation. A mixed-effects model analysis was used for comparison of estimated radiation dose and PET data. RESULTS There was a significant decrease of 15% in the radiation dose estimates between 80 and 120 kVp (DLP 946.2 ± 189 versus 1157.0 ± 236, respectively; p < 0.001). There was an increase of 12% in PET signal in the normal liver with 80 kVp. The average score of PET image quality obtained between 80 and 120 kVp was 4.85 ± 0.42 versus 4.90 ± 0.27, respectively (p = 0.47). CONCLUSION PET/80 kVp CT has no statistically significant difference in the PET image quality and quantitative analysis compared to PET/120 kVp and may be used in selected patients to reduce the radiation dose.
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Affiliation(s)
- H Bernstine
- Department of Nuclear Medicine, Rabin Medical Center, Petah Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - V Sopov
- Department of Nuclear Medicine, Rabin Medical Center, Petah Tikva, Israel
| | - N Yefremov
- Department of Nuclear Medicine, Rabin Medical Center, Petah Tikva, Israel
| | - M Nidam
- Department of Nuclear Medicine, Rabin Medical Center, Petah Tikva, Israel
| | - M Gabbai
- Department of Radiology, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - J Sosna
- Department of Radiology, Hadassah Hebrew University Medical Center, Jerusalem, Israel; Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - D Groshar
- Department of Nuclear Medicine, Rabin Medical Center, Petah Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Nuclear Medicine, Assuta Medical Center, Tel Aviv, Israel.
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Combining automated attenuation-based tube voltage selection and iterative reconstruction: a liver phantom study. Eur Radiol 2013; 24:657-67. [DOI: 10.1007/s00330-013-3049-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 09/27/2013] [Accepted: 10/04/2013] [Indexed: 10/26/2022]
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Low tube voltage intermediate tube current liver MDCT: sinogram-affirmed iterative reconstruction algorithm for detection of hypervascular hepatocellular carcinoma. AJR Am J Roentgenol 2013; 201:23-32. [PMID: 23789655 DOI: 10.2214/ajr.12.10000] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The purpose of this study was to compare image quality and lesion detectability in the evaluation of hypervascular hepatocellular carcinoma (HCC) on low-tube-voltage half-dose liver CT scans subjected to sinogram-affirmed iterative reconstruction (SAFIRE) with the quality and detectability on full-dose scans reconstructed with filtered back projection (FBP). MATERIALS AND METHODS A total of 126 patients with suspected HCC who underwent liver CT including arterial phase scanning at 80 kVp in the dual-source mode (300 mAs for each tube) were included in the study. The half-dose arterial scans were reconstructed with FBP, iterative reconstruction in image space (IRIS), and five SAFIRE strengths (S1-S5) and were compared with full-dose virtual scans (600 mA) reconstructed with FBP. We assessed image noise, contrast-to-noise ratio (CNR) of the liver and blood vessels, and lesionto-liver CNR. Two radiologists evaluated image quality and lesion detectability attained with the different imaging sets. RESULTS Image noise on SAFIRE images was significantly lower than that on the other images, and the CNRs on SAFIRE images were higher than those on half-dose FBP images (p < 0.001). In addition, lesion-to-liver CNR on the half-dose S5 SAFIRE images was higher than on IRIS and full-dose FBP images (p < 0.05). Among the half-dose scans, SAFIRE images had significantly better image quality than FBP images (p < 0.05). Regarding lesion detection, half-dose SAFIRE images were better than half-dose FBP images and were comparable with full-dose FBP images (observer 1, 91.8% vs 96%; observer 2, 98% vs 98%; p > 0.05). CONCLUSION Performing half-dose 80-kVp liver CT with SAFIRE technique may increase image quality and afford comparable lesion detectability of hypervascular HCC at a reduced radiation dose compared with full-dose CT with FBP.
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Deng K, Zhang CQ, Li W, Wang JJ, Wang XY, Pang T, Wang GL, Liu C. Preliminary application of high-definition CT Gemstone Spectral Imaging in hand and foot tendons. Korean J Radiol 2012; 13:743-51. [PMID: 23118573 PMCID: PMC3484295 DOI: 10.3348/kjr.2012.13.6.743] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 04/04/2012] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE To assess the feasibility of visualizing hand and foot tendon anatomy and disorders by Gemstone Spectral Imaging (GSI) high-definition CT (HDCT). MATERIALS AND METHODS Thirty-five patients who suffered from hand or foot pain were scanned with GSI mode HDCT and MRI. Spectrum analysis was used to select the monochromatic images that provide the optimal contrast-to-noise ratio (CNR) for tendons. The image quality at the best selected monochromatic level and the conventional polychromatic images were compared. Tendon anatomy and disease were also analyzed at GSI and MRI. RESULTS The monochromatic images at about 65 keV (mean 65.09 ± 2.98) provided the optimal CNR for hand and foot tendons. The image quality at the optimal selected monochromatic level was superior to conventional polychromatic images (p = 0.005, p < 0.05). GSI was useful in visualizing hand and foot tendon anatomy and disorders. There were no statistical differences between GSI and MRI with regard to tendon thickening (χ(2) = 0, p > 0.05), compression (χ(2) = 0.5, p > 0.05), absence (χ(2) = 0, p > 0.05) and rupture (χ(2) = 0, p > 0.05). GSI was significantly less sensitive than MRI in displaying tendon adhesion (χ(2) = 4.17, p < 0.05), degeneration (χ(2) = 4.17, p < 0.05), and tendinous sheath disease (χ(2) = 10.08, p < 0.05). CONCLUSION GSI with monochromatic images at 65 keV displays clearly the most hand and foot tendon anatomy and disorders with image quality improved, as compared with conventional polychromatic images. It may be used solely or combined with MRI in clinical work, depending on individual patient disease condition.
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Affiliation(s)
- Kai Deng
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan 250014, China
| | - Cheng-Qi Zhang
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan 250014, China
| | - Wei Li
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan 250014, China
| | - Jun-Jun Wang
- The Medical College of Shandong University, Jinan 250012, China
| | - Xin-Yi Wang
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan 250014, China
| | - Tao Pang
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan 250014, China
| | - Guang-Li Wang
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan 250014, China
| | - Cheng Liu
- CT Room, Shandong Medical Imaging Research Institute, Jinan 250021, China
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